CountQueuingStrategy

Baseline 2022

Newly available

Since June 2022, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

Note: This feature is available in Web Workers.

The CountQueuingStrategy interface of the Streams API provides a built-in chunk counting queuing strategy that can be used when constructing streams.

Constructor

CountQueuingStrategy(): Creates a new CountQueuingStrategy object instance.

Instance properties

CountQueuingStrategy.highWaterMark Read only: The total number of chunks that can be contained in the internal queue before backpressure is applied.

Instance methods

CountQueuingStrategy.size(): Always returns 1.

Examples

const queueingStrategy = new CountQueuingStrategy({ highWaterMark: 1 });

const writableStream = new WritableStream(
  {
    // Implement the sink
    write(chunk) {
      // …
    },
    close() {
      // …
    },
    abort(err) {
      console.log("Sink error:", err);
    },
  },
  queueingStrategy,
);

const size = queueingStrategy.size();

Specifications

Specification
Streams Standard # cqs-class

Browser compatibility

BCD tables only load in the browser